U.S. patent application number 16/872770 was filed with the patent office on 2020-12-17 for hybrid vehicle.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. The applicant listed for this patent is TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Shinichi BABA, Tetsuo HORI, Munehiro KATSUMATA, Toru SHIBAMOTO.
Application Number | 20200392877 16/872770 |
Document ID | / |
Family ID | 1000004867936 |
Filed Date | 2020-12-17 |
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United States Patent
Application |
20200392877 |
Kind Code |
A1 |
HORI; Tetsuo ; et
al. |
December 17, 2020 |
HYBRID VEHICLE
Abstract
A hybrid vehicle including an engine, a drive motor, a first oil
pump, and a second oil pump is configured to, during forward
travel, supply components to be cooled or lubricated with oil
discharged from a discharge port of the first oil pump and a
discharge port of the second oil pump via an oil passage, while the
hybrid vehicle is configured to, during reverse travel, compensate
for a driving force by supplying oil discharged from the discharge
port of the second oil pump to the discharge port of the first oil
pump via the oil passage to cause the first oil pump to operate as
a hydraulic motor.
Inventors: |
HORI; Tetsuo; (Toyota-shi,
JP) ; BABA; Shinichi; (Toyota-shi, JP) ;
KATSUMATA; Munehiro; (Toyota-shi, JP) ; SHIBAMOTO;
Toru; (Okazaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYOTA JIDOSHA KABUSHIKI KAISHA |
Toyota-shi |
|
JP |
|
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi
JP
|
Family ID: |
1000004867936 |
Appl. No.: |
16/872770 |
Filed: |
May 12, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01M 7/00 20130101; F01M
1/02 20130101; F01M 2001/0253 20130101; F01P 3/12 20130101; B60K
6/26 20130101; F01P 2005/105 20130101; F01M 1/16 20130101; B60W
10/30 20130101; B60K 6/365 20130101; F01P 5/12 20130101; B60W 10/04
20130101; B60W 10/08 20130101; F01P 2003/006 20130101; B60W 20/00
20130101; B60K 6/24 20130101; B60Y 2200/92 20130101 |
International
Class: |
F01M 1/02 20060101
F01M001/02; B60K 6/24 20060101 B60K006/24; B60K 6/26 20060101
B60K006/26; F01M 7/00 20060101 F01M007/00; F01M 1/16 20060101
F01M001/16; B60W 20/00 20060101 B60W020/00; B60K 6/365 20060101
B60K006/365; F01P 3/12 20060101 F01P003/12; F01P 5/12 20060101
F01P005/12; B60W 10/08 20060101 B60W010/08; B60W 10/04 20060101
B60W010/04; B60W 10/30 20060101 B60W010/30 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 11, 2019 |
JP |
2019-109120 |
Claims
1. A hybrid vehicle comprising: an engine configured as a driving
force source; a drive motor configured as a driving force source; a
first oil pump configured to be mechanically driven by a driving
force that is transmitted via an output part from at least one of
the engines or the drive motor; and a second oil pump configured to
be driven by a driving force from a rotational driving source, the
driving force being different from a driving force that is
transmitted to the output part, wherein during forward travel of
the hybrid vehicle, the hybrid vehicle travels by using at least
one of the engine or the drive motor, during reverse travel of the
hybrid vehicle, the hybrid vehicle uses the drive motor and travels
by transmitting a driving force from the drive motor to a drive
wheel via the output part, and during forward travel of the hybrid
vehicle, the hybrid vehicle is configured to supply components to
be cooled or lubricated with oil discharged from a discharge port
of the first oil pump and a discharge port of the second oil pump
via an oil passage, while during reverse travel of the hybrid
vehicle, the hybrid vehicle is configured to cause the first oil
pump to operate as a hydraulic motor by supplying oil discharged
from the discharge port of the second oil pump to the discharge
port of the first oil pump via the oil passage.
2. The hybrid vehicle according to claim 1, wherein: the oil
passage includes a change-over valve; and the change-over valve is
configured to, during forward travel, switch into a first state
where oil discharged from the discharge port of the first oil pump
and the discharge port of the second oil pump is supplied to the
components to be cooled or lubricated via the oil passage, while
the change-over valve is configured to, during reverse travel,
switch into a second state where oil discharged from the discharge
port of the second oil pump is supplied to the discharge port of
the first oil pump via the oil passage.
3. The hybrid vehicle according to claim 2, wherein the change-over
valve is configured to switch whether to supply oil to at least
part of the components to be cooled or lubricated.
4. The hybrid vehicle according to claim 1, wherein the oil passage
includes an orifice.
5. The hybrid vehicle according to claim 1, wherein the rotational
driving source is the engine.
6. The hybrid vehicle according to claim 5, further comprising a
power distribution mechanism configured to distribute a power of
the engine between a differential motor and the output part,
wherein, during reverse travel, the engine of the hybrid vehicle is
rotated by a power of the differential motor via the power
distribution mechanism.
7. The hybrid vehicle according to claim 1, wherein the rotational
driving source is an electric motor.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Japanese Patent
Application No. 2019-109120 filed on Jun. 11, 2019, incorporated
herein by reference in its entirety.
BACKGROUND
1. Technical Field
[0002] The disclosure relates to provision of a driving force
during reverse travel in a hybrid vehicle that uses an engine and a
motor as driving force sources.
2. Description of Related Art
[0003] A hybrid vehicle that includes an engine and a motor as
driving force sources and that transmits a driving force from the
driving force sources to drive wheels via an output part is known.
This is, for example, the hybrid vehicle described in Japanese
Unexamined Patent Application Publication No. 2017-137991 (JP
2017-137991 A). The hybrid vehicle suggested in JP 2017-137991 A
includes a first oil pump and a second oil pump. The first oil pump
is mechanically driven with the rotation of an output part. The
second oil pump is driven by a rotational driving source different
from the output part. During forward travel, oil discharged from
the first oil pump and the second oil pump is supplied to
components to be cooled or lubricated with oil.
SUMMARY
[0004] In the hybrid vehicle described in JP 2017-137991 A, the
engine and the motor are used as the driving force sources during
forward travel, and only the motor is used as the driving force
source during reverse travel. Therefore, since the driving force of
the engine is not used during reverse travel, shortage of driving
force can occur during reverse travel.
[0005] The disclosure provides a hybrid vehicle that uses an engine
and a motor as driving force sources and that is able to suppress
the shortage of driving force during reverse travel.
[0006] An aspect of the disclosure relates to a hybrid vehicle
including an engine, a drive motor, a first oil pump, and a second
oil pump. The engine is configured as a driving force source. The
drive motor is configured as a driving force source. The first oil
pump is configured to be mechanically driven by a driving force
that is transmitted via an output part from at least one of the
engine or the drive motor. The second oil pump is configured to be
driven by a driving force from a rotational driving source, and the
driving force is different from a driving force transmitted to the
output part. During forward travel of the hybrid vehicle, the
hybrid vehicle travels by using at least one of the engine or the
drive motor, while, during reverse travel of the hybrid vehicle,
the hybrid vehicle uses the drive motor and travels by transmitting
a driving force from the drive motor to a drive wheel via the
output part. During forward travel of the hybrid vehicle, the
hybrid vehicle is configured to supply components to be cooled or
lubricated with oil discharged from a discharge port of the first
oil pump and a discharge port of the second oil pump via an oil
passage, while the oil passage is configured to, during reverse
travel, cause the first oil pump to operate as a hydraulic motor by
supplying oil discharged from the discharge port of the second oil
pump to the discharge port of the first oil pump via the oil
passage.
[0007] With the hybrid vehicle of the above aspect, during reverse
travel, oil discharged from the discharge port of the second oil
pump is supplied to the discharge port of the first oil pump, and
the first oil pump operates as a hydraulic motor. Therefore, a
driving force in a direction to cause the vehicle to move backward
can be generated by the first oil pump. Thus, a driving force
during reverse travel can be compensated, and shortage of driving
force during reverse travel can be resolved.
[0008] In the hybrid vehicle of the above aspect, the oil passage
may include a change-over valve. The change-over valve may be
configured to, during forward travel, switch into a first state
where oil discharged from the discharge port of the first oil pump
and the discharge port of the second oil pump is supplied to the
components to be cooled or lubricated via the oil passage, while
the change-over valve may be configured to, during reverse travel,
switch into a second state where oil discharged from the discharge
port of the second oil pump is supplied to the discharge port of
the first oil pump via the oil passage.
[0009] With the hybrid vehicle of the above aspect, during forward
travel, the change-over valve is switched into the first state, and
oil discharged from the discharge port of the first oil pump and
the discharge port of the second oil pump is supplied to the
components to be cooled or lubricated via the oil passage. On the
other hand, during reverse travel, the change-over valve is
switched into the second state, and oil discharged from the second
oil pump is supplied via the oil passage to the discharge port of
the first oil pump, so the first oil pump can be operated as a
hydraulic motor. In this way, the change-over valve is switched
between the first state and the second state, so the first oil pump
can be operated as a hydraulic motor only during reverse
travel.
[0010] In the hybrid vehicle of the above aspect, the change-over
valve may be configured to switch whether to supply oil to at least
part of the components to be cooled or lubricated.
[0011] With the hybrid vehicle of the above aspect, although oil is
not supplied to part of the components to be cooled or lubricated
during reverse travel, the amount of oil that is supplied to the
first oil pump increases as compared to the case where oil is
supplied to all the components to be cooled or lubricated.
Therefore, a power that is transmitted to the drive wheel can be
increased.
[0012] In the hybrid vehicle of the above aspect, the oil passage
may include an orifice.
[0013] With the hybrid vehicle of the above aspect, during reverse
travel, oil discharged from the second oil pump is supplied to the
discharge port of the first oil pump via the orifice, so the first
oil pump can be operated as a hydraulic motor. In addition, the
amount of oil that is supplied to the discharge port of the first
oil pump during reverse travel can be adjusted by adjusting the
opening degree of the orifice.
[0014] In the hybrid vehicle of the above aspect, the rotational
driving source may be the engine.
[0015] With the hybrid vehicle of the above aspect, during reverse
travel, when the engine that serves as the rotational driving
source is rotated, the second oil pump is driven, and oil
discharged from the discharge port of the second oil pump is
supplied to the discharge port of the first oil pump via the oil
passage. Therefore, during reverse travel, the first oil pump can
be operated as a hydraulic motor.
[0016] The hybrid vehicle of the above aspect may further include a
power distribution mechanism configured to distribute a power of
the engine between a differential motor and the output part. During
reverse travel, the engine of the hybrid vehicle may be rotated by
a power of the differential motor via the power distribution
mechanism.
[0017] With the hybrid vehicle of the above aspect, during reverse
travel, the differential motor is driven, and the power of the
differential motor is transmitted to the engine via the power
distribution mechanism. Therefore, the second oil pump can be
driven.
[0018] In the hybrid vehicle of the above aspect, the rotational
driving source may be an electric motor.
[0019] With the hybrid vehicle of the above aspect, during reverse
travel, the electric motor that serves as the rotational driving
source is driven, and oil discharged from the discharge port of the
second oil pump is supplied to the discharge port of the first oil
pump, so the first oil pump can be operated as a hydraulic
motor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Features, advantages, and technical and industrial
significance of exemplary embodiments of the disclosure will be
described below with reference to the accompanying drawings, in
which like signs denote like elements, and wherein: FIG. 1 is a
skeletal diagram that schematically shows the configuration of a
hybrid vehicle according to a first embodiment of the
disclosure;
[0021] FIG. 2 is a view that shows the flow of energy during
reverse travel in a drivetrain of FIG. 1;
[0022] FIG. 3 is a schematic diagram of a lubrication and cooling
system that is provided in the hybrid vehicle of the first
embodiment and that supplies oil to components to be cooled or
lubricated in the drivetrain of FIG. 1;
[0023] FIG. 4 is a schematic diagram of a lubrication and cooling
system provided in a hybrid vehicle according to a second
embodiment of the disclosure;
[0024] FIG. 5 is a view that shows the flow of energy during
reverse travel in the hybrid vehicle of FIG. 4;
[0025] FIG. 6 is a table that shows modes of combinations of
components to be cooled or lubricated, other than a first oil pump,
which are supplied with oil during reverse travel according to a
third embodiment of the disclosure;
[0026] FIG. 7 is a diagram that shows the structure of a
change-over valve for achieving Mode 2 of FIG. 6;
[0027] FIG. 8 is a diagram that shows the structure of a
change-over valve for achieving Mode 6 of FIG. 6;
[0028] FIG. 9 is a diagram that shows the structure of a
change-over valve for achieving Mode 8 of FIG. 6;
[0029] FIG. 10 is a diagram that shows the structure of a
lubrication and cooling system for achieving Mode 3 and Mode 4 of
FIG. 6;
[0030] FIG. 11 is a schematic diagram of a lubrication and cooling
system provided in a hybrid vehicle according to a fourth
embodiment of the disclosure;
[0031] FIG. 12 is a diagram that shows the schematic configuration
of a hybrid vehicle according to a fifth embodiment of the
disclosure; and
[0032] FIG. 13 is a diagram that shows the schematic configuration
of a hybrid vehicle according to a sixth embodiment of the
disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
[0033] Hereinafter, embodiments of the disclosure will be described
with reference to the accompanying drawings. In the following
embodiments, drawings are simplified or deformed where appropriate,
and the scale ratio, shape, and the like, of each component is not
always drawn accurately.
[0034] FIG. 1 is a skeletal diagram that schematically shows the
configuration of a hybrid vehicle 8 (hereinafter, referred to as
vehicle 8) of a first embodiment of the disclosure. The vehicle 8
includes a vehicle drivetrain 10 (hereinafter, referred to as
drivetrain 10) between an engine 12 and a pair of right and left
drive wheels 14r, 14l (referred to as drive wheels 14 when not
distinguished from each other). The drivetrain 10 is used in a
front-engine, front-wheel drive (FF) hybrid vehicle. The drivetrain
10 is a hybrid drivetrain that transmits a power output from at
least one of the engine 12 or a second electric motor MG2, which
are driving force sources, to the right and left drive wheels 14r,
14l via a differential gear set 20, a pair of right and left axles
22r, 22l, and other components.
[0035] As shown in FIG. 1, the drivetrain 10 includes an input
shaft 23, a planetary gear train 24, a first electric motor MG1, an
output gear 26, a power transmission shaft 34, the second electric
motor MG2, a reduction gear 36, a counter shaft 32, a counter gear
28, a differential drive gear 30, the differential gear set 20, and
the axles 22r, 22l. The input shaft 23 is disposed so as to be
rotatable about a first axis CL1. The planetary gear train 24, the
first electric motor MG1, and the output gear 26 are disposed
radially outward of the input shaft 23. The power transmission
shaft 34 is disposed so as to be rotatable about a second axis CL2.
The second electric motor MG2 is disposed coaxially with the power
transmission shaft 34. The reduction gear 36 is provided on the
power transmission shaft 34. The counter shaft 32 is disposed so as
to be rotatable about a third axis CL3. The counter gear 28 and the
differential drive gear 30 are provided on the counter shaft 32.
The differential gear set 20 and the axles 22r, 22l are disposed so
as to be rotatable about a fourth axis CL4. All of these rotating
members are accommodated in a casing 40 that is a non-rotating
member. The first axis CL1, the second axis CL2, the third axis
CL3, and the fourth axis CL4 each are a rotation axis disposed
parallel to the direction of the vehicle width of the vehicle
8.
[0036] Each of the first electric motor MG1 and the second electric
motor MG2 is an electric motor having at least one of the function
of a motor that generates mechanical power from electric energy or
the function of a generator that generates electric energy from
mechanical power, and is a motor generator that is selectively
operated as a motor or a generator. The first electric motor MG1
has a generator function for providing a reaction force against the
engine 12 and a motor function of driving the engine 12 stopped in
operation. The second electric motor MG2 has a motor function for
serving as a drive motor that outputs driving force as a driving
force source and a generator function of generating electric energy
through regeneration from a counter driving force transmitted from
the drive wheels 14 side. The first electric motor MG1 is an
example of a differential motor of the disclosure. The second
electric motor MG2 is an example of a drive motor of the
disclosure.
[0037] The input shaft 23 is coupled to the engine 12 via a
crankshaft 12a of the engine 12, a damper (not shown), and the
like, such that power is transmittable. The input shaft 23 is
supported by the casing 40 via a bearing 18, and the like, so as to
be rotatable about the first axis CL1.
[0038] The planetary gear train 24 is disposed around the first
axis CL1, and is a single-pinion planetary gear train (differential
mechanism) including a sun gear S, a carrier CA, and a ring gear R.
The planetary gear train 24 functions as a power distribution
mechanism that distributes the power of the engine 12 between the
first electric motor MG1 and the output gear 26. The sun gear S of
the planetary gear train 24 is coupled to the first electric motor
MG1 such that power is transmittable. The carrier CA is coupled to
the engine 12 via the input shaft 23 and the crankshaft 12a such
that power is transmittable. The ring gear R is coupled to the
output gear 26 such that power is transmittable. The ring gear R
and the output gear 26 are made of a composite gear in which these
gears are integrally formed.
[0039] The first electric motor MG1 is placed in position next to
the planetary gear train 24 across a partition wall 56, which is
part of the casing 40, in the direction of the first axis CL1. The
first electric motor MG1 includes an annular stator 42, an annular
rotor 44, and a rotor shaft 46. The stator 42 is fixed to the
casing 40 so as to be non-rotatable. The rotor 44 is disposed
radially inward of the stator 42. The rotor shaft 46 is coupled to
the inner periphery of the rotor 44. A stator coil 48 is wound in
the stator 42. The rotor shaft 46 is rotatably supported by the
casing 40 via a pair of bearings 47a, 47b disposed on both sides in
the axial direction.
[0040] The output gear 26 is coupled to the ring gear R of the
planetary gear train 24 and is in mesh with the counter gear 28
provided on the counter shaft 32.
[0041] The second electric motor MG2 and the reduction gear 36 are
disposed so as to be rotatable about the second axis CL2 and
disposed next to each other across the partition wall 56 in the
direction of the second axis CL2.
[0042] The second electric motor MG2 includes an annular stator 50,
an annular rotor 52, and a rotor shaft 54. The stator 50 is fixed
to the casing 40 so as to be non-rotatable. The rotor 52 is
disposed radially inward of the stator 50. The rotor shaft 54 is
coupled to the inner periphery of the rotor 52. A stator coil 55 is
wound in the stator 50. The rotor shaft 54 is rotatably supported
by the casing 40 via a pair of bearings 57a, 57b disposed on both
sides in the axial direction.
[0043] The reduction gear 36 is provided integrally with the power
transmission shaft 34 and is in mesh with the counter gear 28
provided on the counter shaft 32. The number of teeth of the
reduction gear 36 is set so as to be less than the number of teeth
of the counter gear 28, so the rotation of the second electric
motor MG2 is reduced in speed and transmitted to the counter shaft
32 via the reduction gear 36 and the counter gear 28. The power
transmission shaft 34 is rotatably supported by the casing 40 via a
pair of bearings 59a, 59b disposed on both sides in the axial
direction.
[0044] The counter shaft 32 is rotatably supported by the casing 40
via a pair of bearings 61a, 61b disposed on both sides in the axial
direction.
[0045] The counter gear 28 and the differential drive gear 30 are
provided on the counter shaft 32 so as to be relatively
non-rotatable. The counter shaft 32 rotates about the third axis
CL3. The counter gear 28 is in mesh with the output gear 26 and the
reduction gear 36, and a power output from at least one of the
engine 12 or the second electric motor MG2 is transmitted to the
counter gear 28. The differential drive gear 30 is in mesh with a
differential ring gear 38 of the differential gear set 20.
Therefore, when a power is input from at least one of the output
gear 26 or the reduction gear 36 to the counter gear 28, the power
is transmitted to the differential gear set 20 via the counter
shaft 32 and the differential drive gear 30.
[0046] The differential gear set 20 and the pair of axles 22r, 22l
are disposed so as to be rotatable about the fourth axis CL4. The
differential ring gear 38 of the differential gear set 20 is in
mesh with the differential drive gear 30, so a power output from at
least one of the engine 12 or the second electric motor MG2 is
input from the differential ring gear 38 to the differential gear
set 20.
[0047] The differential gear set 20 is made up of a known
differential mechanism. The differential gear set 20 transmits a
power to the right and left axles 22r, 22l while permitting the
relative rotation between the right and left axles 22r, 22l. Since
the differential gear set 20 is a known technique, the description
thereof is omitted. The differential gear set 20 is rotatably
supported by the casing 40 via a pair of bearings 62a, 62b disposed
on both sides in the direction of the fourth axis CL4.
[0048] The casing 40 is made up of a housing 40a, an axle case 40b,
and a case cover 40c. The axle case 40b has openings at both sides
in the direction of the first axis CL1. The housing 40a is fastened
by bolts to one of the openings of the axle case 40b, and the case
cover 40c is fastened by bolts to the other one of the openings of
the axle case 40b.
[0049] The axle case 40b has the partition wall 56 perpendicular to
the first axis CL1. The inside of the casing 40 is partitioned by
the partition wall 56 into a gear chamber 58 and a motor chamber
60. Various gears, such as the planetary gear train 24, the output
gear 26, the counter gear 28, the reduction gear 36, and the
differential gear set 20, are accommodated in the gear chamber 58.
The first electric motor MG1 and the second electric motor MG2 are
accommodated in the motor chamber 60.
[0050] A pump drive gear 64 is in mesh with the differential ring
gear 38. The pump drive gear 64 is used to drive a differential
gear-driven oil pump P1 (hereinafter, differential gear-driven pump
P1). The differential gear-driven pump P1 is a mechanical oil pump
that is connected to the differential ring gear 38 of the
differential gear set 20 via the pump drive gear 64 such that power
is transmittable. The differential gear-driven pump P1 is
configured to be mechanically driven with the rotation of the
differential ring gear 38 of the differential gear set 20 as the
differential ring gear 38 rotates in a forward travel direction
(forward travel rotation direction) and discharge oil. The
differential gear-driven pump P1 is an example of a first oil pump
of the disclosure. The differential ring gear 38 is an example of
part of an output part of the disclosure.
[0051] A mechanical engine-driven oil pump P2 (hereinafter,
engine-driven pump P2) is provided along the first axis CL1 at an
end of the input shaft 23 in the axial direction across from the
engine 12. The engine-driven pump P2 is driven by the engine 12. A
drive gear (not shown) that is a component of the engine-driven
pump P2 is connected to a shaft end portion of the input shaft 23.
The engine-driven pump P2 is driven with the rotation of the engine
12. Therefore, the engine 12 functions as a rotational driving
source of the engine-driven pump P2, and oil is discharged from the
engine-driven pump P2 as the engine 12 rotates. In this way, the
rotational driving source of the engine-driven pump P2 that is
driven by the engine 12 is different from a rotational driving
source of the differential gear-driven pump P1 that is driven by
the differential ring gear 38. The engine-driven pump P2 is an
example of a second oil pump of the disclosure. The engine 12 is an
example of a rotational driving source different from that of the
output part in the disclosure.
[0052] In the thus configured drivetrain 10, the power of the
engine 12 is transmitted to the right and left drive wheels 14r,
14l via the planetary gear train 24, the output gear 26, the
counter gear 28, the counter shaft 32, the differential drive gear
30, the differential gear set 20, and the axles 22r, 22l. The power
of the second electric motor MG2 is transmitted to the right and
left drive wheels 14r, 14l via the rotor shaft 54, the power
transmission shaft 34, the reduction gear 36, the counter gear 28,
the counter shaft 32, the differential drive gear 30, the
differential gear set 20, and the axles 22r, 22l. In the
specification, power is synonymous with torque and driving force.
In the first embodiment, members mechanically coupled to the drive
wheels 14, that is, members that are rotated with the drive wheels
14, are examples of the output part of the disclosure.
Specifically, examples of the output part of the disclosure include
the output gear 26, the counter gear 28, the differential drive
gear 30, the counter shaft 32, the power transmission shaft 34, the
reduction gear 36, the differential gear set 20 including the
differential ring gear 38, and the right and left axles 22r,
22l.
[0053] The vehicle 8 is able to travel in a motor drive mode (EV
mode) or a hybrid drive mode (HV mode). In the motor drive mode (EV
mode), the vehicle 8 travels by using the second electric motor
MG2. In the hybrid drive mode (HV mode), the vehicle 8 travels by
using the engine 12 and the second electric motor MG2. The drive
mode is shifted as needed between the EV mode and the HV mode in
accordance with, for example, a predetermined shift map using
required driving force (such as accelerator operation amount) and
vehicle speed as parameters.
[0054] In the EV mode, the vehicle 8 travels by using only the
second electric motor MG2 as the driving force source while the
engine 12 is stopped. The EV mode is used in a relatively low-load,
low vehicle speed region. Even in a driving region in which the EV
mode is used, when the state of charge (remaining level of charge)
of a battery 66 (see FIG. 2) is low, the engine 12 is driven and
regenerative control with the use of the first electric motor MG1
is executed, and an electric power obtained as a result of the
regenerative control is stored in the battery 66.
[0055] In the HV mode, the vehicle 8 travels forward by using the
engine 12 and the second electric motor MG2 as the driving force
sources. The HV mode is used in a higher-load, higher-vehicle speed
region than those of the driving region in which the EV mode is
used. In the HV mode, the power of the engine 12 is distributed by
the planetary gear train 24 between the output gear 26 and the
first electric motor MG1, and the power distributed to the output
gear 26 is transmitted to the drive wheels 14 via the differential
gear set 20, and other components, as a driving force (the direct
torque of the engine 12) for propelling the vehicle 8. With the
power distributed to the first electric motor MG1, regenerative
control over the first electric motor MG1 is executed, and an
electric power is generated by the first electric motor MG1. An
electric power generated by the first electric motor MG1 is
supplied to the second electric motor MG2 or stored in the battery
66. The second electric motor MG2 generates a power by using at
least one of an electric power stored in the battery 66 or an
electric power generated by the first electric motor MG1 and
transmits the power to the drive wheels 14. In this way, in the HV
mode, the vehicle 8 travels forward by using the engine 12 and the
second electric motor MG2.
[0056] During reverse travel, the vehicle 8 travels by using only
the second electric motor MG2 as the driving force source while the
engine 12 is stopped. In this way, during reverse travel, the
vehicle 8 travels by using only the second electric motor MG2;
however, since no power is transmitted from the engine 12, there
are concerns about shortage of driving force. In this regard,
during reverse travel, oil is discharged from a discharge port 84b
(see FIG. 3) of the engine-driven pump P2 by driving the
engine-driven pump P2, and the oil discharged from the
engine-driven pump P2 is supplied to a discharge port 82b (see FIG.
3) of the differential gear-driven pump P1. As a result, the
differential gear-driven pump P1 is operated as a hydraulic motor,
and a power generated by the differential gear-driven pump P1 is
transmitted to the drive wheels 14 via the differential gear set
20.
[0057] FIG. 2 shows the flow of energy in the drivetrain 10 during
reverse travel in the first embodiment. In FIG. 2, the battery 66
and a power control unit (PCU) 68 are shown at the top. The battery
66 is used to supply an electric power to drive the first electric
motor MG1 and the second electric motor MG2. The PCU 68 controls
the drive statuses of the first electric motor MG1 and second
electric motor MG2.
[0058] The outlined arrows drawn from the battery 66 and the PCU 68
toward the first electric motor MG1 and the second electric motor
MG2 respectively represent the flows of electric energy to be
supplied to the first electric motor MG1 and the second electric
motor MG2. In other words, during reverse travel, the first
electric motor MG1 and the second electric motor MG2 are driven by
an electric power from the battery 66.
[0059] The solid arrow between the first electric motor MG1 and the
engine 12 represents energy (mechanical energy) that is used to
rotate the engine 12 with the first electric motor MG1. The first
electric motor MG1 rotates the engine 12 (motoring) via the
planetary gear train 24 by using an electric power from the battery
66. In this way, during reverse travel, the engine 12 is rotated
via the planetary gear train 24 by the power of the first electric
motor MG1.
[0060] The solid arrow between the second electric motor MG2 and
the drive wheels 14 represents the flow of energy (mechanical
energy) that is used by the second electric motor MG2 to cause the
vehicle 8 to travel backward. The second electric motor MG2 causes
the vehicle 8 to travel backward by transmitting a power that acts
in a reverse travel direction (reverse travel rotation direction)
to the drive wheels 14 via the differential gear set 20 and other
components.
[0061] The solid arrow between the engine 12 and the engine-driven
pump P2 represents the flow of energy (mechanical energy) that is
used to drive the engine-driven pump P2 with the engine 12. Since
the engine-driven pump P2 is connected to the engine 12 such that
power is transmittable, the engine 12 is rotated as a result of
motoring of the engine 12 with the use of the first electric motor
MG1, so the engine-driven pump P2 is driven.
[0062] The diagonally-shaded arrow between the engine-driven pump
P2 and the differential gear-driven pump P1 represents a hydraulic
path through which oil that is discharged from the discharge port
84b of the engine-driven pump P2 is supplied to the discharge port
82b of the differential gear-driven pump P1. When oil discharged
from the discharge port 84b of the engine-driven pump P2 is
supplied to the discharge port 82b of the differential gear-driven
pump P1, the differential gear-driven pump P1 is rotated in the
reverse direction relative to the rotation during forward travel.
At this time, a power that acts in a direction to cause the vehicle
8 to travel backward is generated in the differential gear-driven
pump P1. In this way, during reverse travel, oil is supplied to the
discharge port 82b of the differential gear-driven pump P1, with
the result that the differential gear-driven pump P1 operates as a
hydraulic motor that generates a power that acts in the reverse
travel direction.
[0063] The solid arrow between the differential gear-driven pump P1
and the drive wheels 14 represents the flow of energy (mechanical
energy) that transmits a power generated in the differential
gear-driven pump P1 to the drive wheels 14 via the differential
gear set 20. Since the differential gear-driven pump P1 is coupled
to the differential gear set 20 via the pump drive gear 64 such
that power is transmittable, a power generated by the differential
gear-driven pump P1 is transmitted to the drive wheels 14 via the
differential gear set 20 and other components.
[0064] As described above, during reverse travel of the vehicle 8,
the differential gear-driven pump P1 is operated as a hydraulic
motor, and a power generated in the differential gear-driven pump
P1 to act in the reverse travel direction is transmitted to the
drive wheels 14 via the differential gear set 20 and other
components. Hence, shortage of driving force during reverse travel
of the vehicle 8 is resolved. In addition, during reverse travel,
the engine 12 is rotated through motoring by the first electric
motor MG1, so a power that acts in a direction to interfere with
reverse travel and that is generated when the engine 12 is caused
to autonomously operate is not generated.
[0065] FIG. 3 is a schematic diagram of a lubrication and cooling
system 70 for supplying oil to components to be cooled or
lubricated in the drivetrain 10, and shows a structure that, during
reverse travel, allows oil discharged from the discharge port 84b
of the engine-driven pump P2 to be supplied to the discharge port
82b of the differential gear-driven pump P1.
[0066] The lubrication and cooling system 70 is configured to be
able to supply oil discharged from the differential gear-driven
pump P1 or the engine-driven pump P2 to the components to be cooled
or lubricated in the drivetrain 10. The components to be cooled or
lubricated correspond to components that require lubrication and
cooling during travel and correspond to the first electric motor
MG1, the second electric motor MG2, the gears 24, 26, 28, 30, 36,
38, and the like, in the gear chamber 58, the bearings 18, 59a,
59b, 61a, 61b, 62a, 62b in the gear chamber 58, and the like, in
the drivetrain 10.
[0067] The lubrication and cooling system 70 includes a
differential gear-driven pump P1, an engine-driven pump P2, a first
oil passage 72, a second oil passage 74, a change-over valve 78,
and an oil pan 80. The first oil passage 72 is an oil passage for
supplying oil discharged from the discharge port 82b of the
differential gear-driven pump P1 to the gears 24, 26, 28, 30, 36,
38, and the like, in the gear chamber 58 and the bearings 18, 59a,
59b, 61a, 61b, 62a, 62b in the gear chamber 58. The second oil
passage 74 is an oil passage for supplying oil discharged from the
discharge port 84b of the engine-driven pump P2 to the first
electric motor MG1, the second electric motor MG2, the gears of the
planetary gear train 24, and bearings (not shown) that support the
gears of the planetary gear train 24. The change-over valve 78 is
inserted between the first oil passage 72 and the second oil
passage 74. Oil inside the casing 40 is pooled in the oil pan 80.
The gears and bearings of the planetary gear train 24 are supplied
with oil from both the first oil passage 72 ad the second oil
passage 74.
[0068] The differential gear-driven pump P1 is connected to the
differential ring gear 38 of the differential gear set 20 via the
pump drive gear 64 such that power is transmittable. Therefore,
when the differential ring gear 38 rotates during forward travel of
the vehicle 8, the differential gear-driven pump P1 is mechanically
driven via the pump drive gear 64. At this time, oil pooled in the
oil pan 80 is pumped, introduced from a suction port 82a of the
differential gear-driven pump P1, and discharged from the discharge
port 82b of the differential gear-driven pump P1. The oil
discharged from the discharge port 82b is supplied to the first oil
passage 72.
[0069] Since the engine-driven pump P2 is connected to the engine
12 via the input shaft 23 such that power is transmittable, the
engine-driven pump P2 is driven with the rotation of the engine 12.
For example, when the engine 12 rotates during the HV mode, the
engine-driven pump P2 is driven.
[0070] When the engine-driven pump P2 is driven, oil pooled in the
oil pan 80 is pumped, introduced from a suction port 84a of the
engine-driven pump P2, and discharged from the discharge port 84b
of the engine-driven pump P2. The oil discharged from the discharge
port 84b of the engine-driven pump P2 is supplied to the second oil
passage 74.
[0071] The first oil passage 72 connects the differential
gear-driven pump P1 with the gears in the gear chamber 58 and the
bearings in the gear chamber 58. Therefore, oil discharged from the
differential gear-driven pump P1 is supplied to the gears in the
gear chamber 58 and the bearings in the gear chamber 58 through the
first oil passage 72. The change-over valve 78 is inserted in the
first oil passage 72. The change-over valve 78 is able to
communicate or interrupt the first oil passage 72. The first oil
passage 72 is divided into a first input oil passage 72a and a
first output oil passage 72b at a boundary set to the change-over
valve 78. The first input oil passage 72a is defined as a part of
the first oil passage 72, connected to the differential gear-driven
pump P1, for the sake of convenience. The first output oil passage
72b is defined as the other part of the first oil passage 72,
connected to the gears in the gear chamber 58 and the bearings in
the gear chamber 58, for the sake of convenience.
[0072] The second oil passage 74 connects the engine-driven pump P2
with the first electric motor MG1, the second electric motor MG2,
and the gears and bearings of the planetary gear train 24.
Therefore, oil discharged from the engine-driven pump P2 is
supplied to the first electric motor MG1, the second electric motor
MG2, and the gears and bearings of the planetary gear train 24
through the second oil passage 74. The change-over valve 78 is
inserted in the second oil passage 74. The change-over valve 78 is
able to communicate or interrupt the second oil passage 74. The
second oil passage 74 is divided into a second input oil passage
74a and a second output oil passage 74b with a boundary set to the
change-over valve 78. The second input oil passage 74a is defined
as a part of the second oil passage 74, connected to the
engine-driven pump P2, for the sake of convenience. The second
output oil passage 74b is defined as the other part of the second
oil passage 74, connected to the first electric motor MG1, the
second electric motor MG2, and the gears and bearings of the
planetary gear train 24, for the sake of convenience.
[0073] The change-over valve 78 is inserted between the first oil
passage 72 and the second oil passage 74. The change-over valve 78
is configured to be able to switch between a first state and a
second state. In the first state, oil discharged from the
differential gear-driven pump P1 is supplied to the gears in the
gear chamber 58 and the bearings in the gear chamber 58, and oil
discharged from the engine-driven pump P2 is supplied to the first
electric motor MG1, the second electric motor MG2, and the gears
and bearings of the planetary gear train 24. In the second state,
oil discharged from the discharge port 84b of the engine-driven
pump P2 is supplied to the discharge port 82b of the differential
gear-driven pump P1. The change-over valve 78 is switched into the
first state during forward travel of the vehicle 8, and switched
into the second state during reverse travel of the vehicle 8.
[0074] The change-over valve 78 includes a first port 86, a second
port 88, a third port 90, a fourth port 92, a spool valve element
(not shown), a spring 94, and a solenoid 96. The first port 86 is
connected to the first input oil passage 72a. The second port 88 is
connected to the first output oil passage 72b. The third port 90 is
connected to the second input oil passage 74a. The fourth port 92
is connected to the second output oil passage 74b. The spool valve
element is used to change the status of communication among the
first port 86, the second port 88, the third port 90, and the
fourth port 92. The spring 94 urges the spool valve element to a
position in which the change-over valve 78 is placed in the first
state. The solenoid 96 is used to, when energized, move the spool
valve element to a position in which the change-over valve 78 is
placed in the second state.
[0075] FIG. 3 shows a state where, during forward travel of the
vehicle 8, the change-over valve 78 is switched into the
above-described first state. At this time, the first port 86 and
the second port 88 communicate with each other, and the third port
90 and the fourth port 92 communicate with each other. Therefore,
the first input oil passage 72a and the first output oil passage
72b are connected via the change-over valve 78, and oil discharged
from the discharge port 82b of the differential gear-driven pump P1
is supplied to the gears in the gear chamber 58 and the bearings in
the gear chamber 58 through the first oil passage 72. In addition,
the second input oil passage 74a and the second output oil passage
74b are connected via the change-over valve 78, and oil discharged
from the discharge port 84b of the engine-driven pump P2 is
supplied to the first electric motor MG1, the second electric motor
MG2, and the gears and bearings of the planetary gear train 24
through the second oil passage 74. In this way, during forward
travel, oil discharged from the discharge port 82b of the
differential gear-driven pump P1 or discharge from the discharge
port 84b of the engine-driven pump P2 is supplied to the components
to be cooled or lubricated in the drivetrain 10.
[0076] On the other hand, during reverse travel of the vehicle 8,
the change-over valve 78 is switched into the above-described
second state. During reverse travel, when the solenoid 96 is
energized, a thrust that acts in a direction against the urging
force of the spring 94 is applied to the spool valve element of the
change-over valve 78. As a result, the spool valve element is moved
against the urging force of the spring 94, and the change-over
valve 78 is switched into the second state. At this time, in the
change-over valve 78, the first port 86 and the third port 90
communicate with each other, while communication between the first
port 86 and the second port 88 and communication between the third
port 90 and the fourth port 92 are interrupted. Therefore, the
second input oil passage 74a is connected to the first input oil
passage 72a via the change-over valve 78, so, as represented by the
diagonally-shaded arrows, oil discharged from the discharge port
84b of the engine-driven pump P2 is supplied to the discharge port
82b of the differential gear-driven pump P1 via the second input
oil passage 74a, the change-over valve 78, and the first input oil
passage 72a.
[0077] The first input oil passage 72a, the second input oil
passage 74a, and the change-over valve 78 make up an oil passage 98
that supplies oil discharged from the discharge port 84b of the
engine-driven pump P2 to the discharge port 82b of the differential
gear-driven pump P1 during reverse travel. The change-over valve 78
is configured to, during forward travel, be switched into the first
state where oil discharged from the discharge port 82b of the
differential gear-driven pump P1 or discharged from the discharge
port 84b of the engine-driven pump P2 to the components to be
cooled or lubricated via the oil passage 98, while the change-over
valve 78 is configured to, during reverse travel, be switched into
the second state where oil discharged from the discharge port 84b
of the engine-driven pump P2 is supplied to the discharge port 82b
of the differential gear-driven pump P1 via the oil passage 98.
[0078] Thus, during reverse travel, the differential gear-driven
pump P1 is rotated in the reverse direction by oil discharged from
the discharge port 84b of the engine-driven pump P2, and the
differential gear-driven pump P1 operates as a hydraulic motor that
generates a power to act in the reverse travel direction. Then, the
power generated by the differential gear-driven pump P1 is
transmitted to the drive wheels 14 through the differential gear
set 20 and other components. In this way, during reverse travel, in
addition to a power that is output from the second electric motor
MG2 and that acts in the reverse travel direction, a power that is
generated by the differential gear-driven pump P1 and that acts in
the reverse travel direction is applied, so shortage of driving
force during reverse travel is resolved.
[0079] As described above, according to the first embodiment,
during reverse travel, oil discharged from the discharge port 84b
of the engine-driven pump P2 is supplied to the discharge port 82b
of the differential gear-driven pump P1, and the differential
gear-driven pump P1 operates as a hydraulic motor, so a driving
force in a direction to cause the vehicle 8 to travel backward can
be generated by the differential gear-driven pump P1. Thus, a
driving force during reverse travel can be compensated, and
shortage of driving force during reverse travel can be
resolved.
[0080] According to the first embodiment, during forward travel,
the change-over valve 78 is switched into the first state, and the
oil passage that connects the discharge port 82b of the
differential gear-driven pump P1 and the discharge port 84b of the
engine-driven pump P2 is interrupted. In this state, oil discharged
from the discharge port 82b of the differential gear-driven pump P1
and oil discharged from the discharge port 84b of the engine-driven
pump P2 each are supplied to the components to be cooled or
lubricated in the drivetrain 10 via an associated one of the first
input oil passage 72a and the second input oil passage 74a. On the
other hand, during reverse travel, the change-over valve 78 is
switched into the second state, and the oil passage that connects
the discharge port 82b of the differential gear-driven pump P1 and
the discharge port 84b of the engine-driven pump P2 is
communicated. In this state, oil discharged from the discharge port
84b of the engine-driven pump P2 is supplied to the discharge port
82b of the differential gear-driven pump P1 via the second input
oil passage 74a and the first input oil passage 72a. As a result,
the differential gear-driven pump P1 can be operated as a hydraulic
motor. In this way, by switching the change-over valve 78 between
the first state and the second state, the differential gear-driven
pump P1 can be operated as a hydraulic motor only during reverse
travel.
[0081] According to the first embodiment, during reverse travel,
the engine-driven pump P2 can be driven by driving the first
electric motor MG1 and transmitting the power of the first electric
motor MG1 to the engine 12 via the planetary gear train 24.
[0082] Next, other embodiments of the disclosure will be described.
Like reference signs denote portions common to the above-described
first embodiment in the following description, and the description
thereof will not be repeated.
[0083] FIG. 4 is a schematic diagram of a lubrication and cooling
system 102 provided in a hybrid vehicle 100 (hereinafter, referred
to as vehicle 100) according to a second embodiment of the
disclosure. When the lubrication and cooling system 102 of FIG. 4
is compared with the lubrication and cooling system 70 of the
above-described first embodiment, an electric oil pump EOP that is
driven by an electric motor 108 is used instead of the
engine-driven pump P2 that is driven by the engine 12 of the
above-described first embodiment. The other structure is the same
as that of the lubrication and cooling system 70 of the
above-described first embodiment, so the description thereof is
omitted. The electric oil pump EOP is an example of the second oil
pump of the disclosure.
[0084] As shown in FIG. 4, the electric oil pump EOP is driven by
the electric motor 108 that serves as a rotational driving source.
When the electric oil pump EOP is driven, oil pooled in the oil pan
80 is pumped, introduced from a suction port 104 of the electric
oil pump EOP, and discharged from a discharge port 106. The oil
discharged from the discharge port 106 is supplied to the second
oil passage 74. The electric oil pump EOP is driven as needed
according to the traveling condition of the vehicle 100. In a
traveling condition in which the temperatures of the first electric
motor MG1 and second electric motor MG2 are easy to increase, for
example, during travel at a high load on the first electric motor
MG1 and the second electric motor MG2, or the like, the electric
oil pump EOP is driven, and oil is discharged from the electric oil
pump EOP. Thus, oil discharged from the electric oil pump EOP is
supplied to the first electric motor MG1, the second electric motor
MG2, and the gears and bearings of the planetary gear train 24
through the second oil passage 74, so the first electric motor MG1
and the second electric motor MG2 are efficiently cooled.
[0085] During reverse travel of the vehicle 100, the electric oil
pump EOP is driven. During reverse travel, the change-over valve 78
is switched into the above-described second state, and the first
port 86 and the third port 90 are communicated. Therefore, oil
discharged from the discharge port 106 of the electric oil pump EOP
is supplied to the discharge port 82b of the differential
gear-driven pump P1 through the second input oil passage 74a, the
change-over valve 78, and the first input oil passage 72a. Thus,
the differential gear-driven pump P1 is rotated in the reverse
direction by oil that is discharged from the electric oil pump EOP,
and the differential gear-driven pump P1 is operated as a hydraulic
motor.
[0086] FIG. 5 shows the flow of energy during reverse travel in the
vehicle 100. As shown in FIG. 5, during reverse travel, when an
electric power is supplied from the battery 66 to the second
electric motor MG2, a power that causes the vehicle 100 to travel
backward is output from the second electric motor MG2, and a power
to act in the reverse travel direction is transmitted to the drive
wheels 14 via the differential gear set 20.
[0087] The electric oil pump EOP is driven by using an electric
power from the battery 66, and oil is discharged from the discharge
port 106 of the electric oil pump EOP. Here, during reverse travel,
the change-over valve 78 is switched into the second state, so oil
discharged from the discharge port 106 of the electric oil pump EOP
is supplied to the discharge port 82b of the differential
gear-driven pump P1 through the second input oil passage 74a, the
change-over valve 78, and the first input oil passage 72a. The
diagonally-shaded arrow in FIG. 5 represents the flow (hydraulic
path) of the above-described oil.
[0088] When oil is supplied to the discharge port 82b of the
differential gear-driven pump P1, the differential gear-driven pump
P1 is rotated in the reverse direction, and the differential
gear-driven pump P1 operates as a hydraulic motor that generates a
power to act in the reverse travel direction. Therefore, a power
generated in the differential gear-driven pump P1 is transmitted to
the drive wheels 14 via the differential gear set 20, and a power
that acts in the reverse travel direction is applied to the drive
wheels 14.
[0089] In this way, even when the electric oil pump EOP is used
instead of the engine-driven pump P2 of the above-described first
embodiment, the differential gear-driven pump P1 can be operated as
a hydraulic motor by driving the electric oil pump EOP and
supplying oil discharged from the electric oil pump EOP to the
discharge port 82b of the differential gear-driven pump P1 during
reverse travel. As a result, a power that is generated in the
differential gear-driven pump P1 and that acts in the reverse
travel direction is transmitted to the drive wheels 14 via the
differential gear set 20, so shortage of driving force during
reverse travel is resolved. Therefore, according to the second
embodiment as well, similar advantageous effects to those of the
above-described first embodiment are obtained.
[0090] In the above-described first embodiment, when the
change-over valve 78 is switched into the second state during
reverse travel, the first oil passage 72 and the second oil passage
74 are interrupted, and supply of oil to the gears and bearings in
the gear chamber 58, the first electric motor MG1, the second
electric motor MG2, and the like, is interrupted. However, even in
a state where the change-over valve 78 is switched into the second
state during reverse travel, oil may be supplied to the gears, and
the like, in the gear chamber 58 as needed.
[0091] FIG. 6 is a table that shows modes of combinations of
components to be cooled or lubricated, other than the differential
gear-driven pump P1, during reverse travel according to a third
embodiment. In FIG. 6, "GEARS AND BEARINGS IN GEAR CHAMBER"
correspond to the gears in the gear chamber 58 and the bearings in
the gear chamber 58, which are the components to be cooled or
lubricated, "MG" corresponds to the first electric motor MG1 and
the second electric motor MG2, which are the components to be
cooled or lubricated, and "GEARS AND BEARINGS OF PLANETARY GEAR
TRAIN" correspond to the gears and bearings of the planetary gear
train 24, which are the components to be cooled or lubricated. In
FIG. 6, "SUPPLIED" indicates that oil is supplied during reverse
travel, and "NOT SUPPLIED" indicates that oil is not supplied
during reverse travel.
[0092] Mode 1 shown in FIG. 6 corresponds to the mode in which,
during reverse travel, oil is supplied to the differential
gear-driven pump P1, but oil is not supplied to none of the
components to be cooled or lubricated. Mode 1 corresponds to the
above-described first embodiment. In this case, during reverse
travel, oil is not supplied to the components to be cooled or
lubricated; however, the amount of oil that is supplied to the
differential gear-driven pump P1 is greater than those of the other
modes (Mode 2 to Mode 8), so a power that is transmitted to the
drive wheels 14 is the greatest among all the modes.
[0093] Mode 2 shown in FIG. 6 indicates that, during reverse
travel, oil is supplied to the differential gear-driven pump P1,
the gears in the gear chamber 58, and the bearings in the gear
chamber 58. Mode 3 indicates that, during reverse travel, oil is
supplied to the differential gear-driven pump P1, the first
electric motor MG1, and the second electric motor MG2. Mode 4
indicates that, during reverse travel, oil is supplied to the
differential gear-driven pump P1, and the gears and bearings of the
planetary gear train 24. Mode 5 indicates that oil is supplied to
the differential gear-driven pump P1, the gears in the gear chamber
58, the bearings in the gear chamber 58, the first electric motor
MG1, and the second electric motor MG2. Mode 6 indicates that oil
is supplied to the differential gear-driven pump P1, the first
electric motor MG1, the second electric motor MG2, and the gears
and bearings of the planetary gear train 24. Mode 7 indicates that
oil is supplied to the differential gear-driven pump P1, the gears
in the gear chamber 58, the bearings in the gear chamber 58, and
the gears and bearings of the planetary gear train 24. Mode 8
indicates that oil is supplied to the differential gear-driven pump
P1, the gears in the gear chamber 58, the bearings in the gear
chamber 58, the first electric motor MG1, the second electric motor
MG2, and the gears and bearings of the planetary gear train 24.
[0094] As shown in Mode 2 to Mode 8, during reverse travel, oil may
also be supplied to the components to be cooled or lubricated as
needed in addition to the differential gear-driven pump P1. Thus,
even during reverse travel, lubrication and cooling of the
components to be cooled or lubricated are ensured. In Mode 2 to
Mode 8, oil is also supplied to components other than the
differential gear-driven pump P1 during reverse travel, and the
amount of oil that is supplied to the differential gear-driven pump
P1 is less than that of Mode 1, so a power that is generated in the
differential gear-driven pump P1 during reverse travel also
decreases.
[0095] In implementing the modes (Mode 2 to Mode 8), the structure
of the lubrication and cooling system is modified according to the
modes. For example, when Mode 2 is implemented, the change-over
valve 78 is replaced with a change-over valve 120 shown in FIG. 7
in the lubrication and cooling system 70 of FIG. 2. FIG. 7 shows a
state where the change-over valve 120 is switched into a second
state, that is, a state during reverse travel.
[0096] The change-over valve 120 is configured, during reverse
travel, such that a first port 122 connected to the first input oil
passage 72a, a second port 124 connected to the first output oil
passage 72b, and a third port 126 connected to the second input oil
passage 74a are communicated while a fourth port 128 connected to
the second output oil passage 74b is interrupted, as shown in FIG.
7.
[0097] When the status of communication of the change-over valve
120 is changed as described above, oil discharged from the
engine-driven pump P2 is supplied to the discharge port 82b of the
differential gear-driven pump P1 through the second input oil
passage 74a, the change-over valve 120, and the first input oil
passage 72a and is also supplied to the gears in the gear chamber
58 and the bearings in the gear chamber 58 through the first output
oil passage 72b during reverse travel. Therefore, the differential
gear-driven pump P1 operates as a hydraulic motor, so a power
generated in the differential gear-driven pump P1 to act in the
reverse travel direction can be transmitted to the drive wheels 14,
and oil can be supplied to the gears in the gear chamber 58 and the
bearings in the gear chamber 58.
[0098] When the change-over valve 78 is replaced with a change-over
valve 140 shown in FIG. 8 in the lubrication and cooling system 70
of FIG. 2, Mode 6 in FIG. 6 is implemented. FIG. 8 shows a state
where the change-over valve 140 is switched into a second state,
that is, a state during reverse travel. As shown in FIG. 8, the
change-over valve 140 is configured, during reverse travel, such
that a first port 142 connected to the first input oil passage 72a,
a third port 146 connected to the second input oil passage 74a, and
a fourth port 148 connected to the second output oil passage 74b
are communicated while a second port 144 connected to the first
output oil passage 72b is interrupted.
[0099] When the status of communication of the change-over valve
140 is changed as described above, oil discharged from the
engine-driven pump P2 is supplied to the discharge port 82b of the
differential gear-driven pump P1 through the second input oil
passage 74a, the change-over valve 140, and the first input oil
passage 72a and is also supplied to the first electric motor MG1,
the second electric motor MG2, and the gears and bearings of the
planetary gear train 24 through the second output oil passage 74b
during reverse travel. Therefore, the differential gear-driven pump
P1 operates as a hydraulic motor, so a power generated in the
differential gear-driven pump P1 to act in the reverse travel
direction can be transmitted to the drive wheels 14, the first
electric motor MG1 and the second electric motor MG2 can be cooled,
and the gears and bearings of the planetary gear train 24 can be
lubricated.
[0100] When the change-over valve 78 is replaced with a change-over
valve 160 shown in FIG. 9 in the lubrication and cooling system 70
of FIG. 2, Mode 8 in FIG. 6 is implemented. FIG. 9 shows a state
where the change-over valve 160 is switched into a second state,
that is, a state during reverse travel. As shown in FIG. 9, the
change-over valve 160 is configured, during reverse travel, such
that a first port 162 connected to the first input oil passage 72a,
a second port 164 connected to the first output oil passage 72b, a
third port 166 connected to the second input oil passage 74a, and a
fourth port 168 connected to the second output oil passage 74b are
communicated.
[0101] When the status of communication of the change-over valve
160 is switched as described above, oil discharged from the
engine-driven pump P2 is supplied to the discharge port 82b of the
differential gear-driven pump P1 through the second input oil
passage 74a, the change-over valve 160, and the first input oil
passage 72a during reverse travel. In addition, oil discharged from
the engine-driven pump P2 is supplied to the first output oil
passage 72b and the second output oil passage 74b through the
change-over valve 160, so oil is supplied to the gears in the gear
chamber 58, the bearings in the gear chamber 58, the first electric
motor MG1, the second electric motor MG2, and the gears and
bearings of the planetary gear train 24.
[0102] As shown in FIG. 10, when the change-over valve 78 is
replaced with the change-over valve 140 shown in FIG. 8 in the
lubrication and cooling system 70 of FIG. 2 and an oil supply
destination change-over valve 170 configured to switch the
destination to be supplied with oil to one of a set of the first
electric motor MG1 and the second electric motor MG2 and a set of
the gears and bearings of the planetary gear train 24 is added to
the second output oil passage 74b, Mode 3 and Mode 4 shown in FIG.
6 are implemented. Although not shown in the drawing, when the
change-over valve 78 is replaced with the change-over valve 160
shown in FIG. 9 in the lubrication and cooling system 70 of FIG. 2
and the above-described oil supply destination change-over valve
170 is added to the second output oil passage 74b, Mode 5 and Mode
7 shown in FIG. 6 are implemented.
[0103] As described above, even when part of oil discharged from
the discharge port 84b of the engine-driven pump P2 is supplied to
the components to be cooled or lubricated during reverse travel,
the remaining part of oil discharged from the discharge port 84b of
the engine-driven pump P2 is supplied to the discharge port 82b of
the differential gear-driven pump P1. Therefore, similar
advantageous effects to those of the above-described first and
second embodiments are obtained.
[0104] FIG. 11 is a schematic diagram of a lubrication and cooling
system 182 provided in a hybrid vehicle 180 according to a fourth
embodiment of the disclosure. When the lubrication and cooling
system 182 of FIG. 11 is compared with the lubrication and cooling
system 70 of the above-described first embodiment, the change-over
valve 78 is replaced with an orifice 184. The other structure is
the same as that of the lubrication and cooling system 70 of the
above-described first embodiment, so the description thereof is
omitted.
[0105] As shown in FIG. 11, oil discharged from the discharge port
82b of the differential gear-driven pump P1 is supplied to the
gears in the gear chamber 58 and the bearings in the gear chamber
58 through a first oil passage 186. In addition, oil discharged
from the discharge port 84b of the engine-driven pump P2 is
supplied to the first electric motor MG1, the second electric motor
MG2, and the gears and bearings of the planetary gear train 24
through a second oil passage 188.
[0106] A coupling oil passage 190 that connects the first oil
passage 186 and the second oil passage 188 is provided, and the
orifice 184 is provided in the coupling oil passage 190. Therefore,
part of oil discharged from the discharge port 84b of the
engine-driven pump P2 can be supplied to the discharge port 82b of
the differential gear-driven pump P1 through the coupling oil
passage 190. Thus, part of the first oil passage 186, the coupling
oil passage 190, and part of the second oil passage 188 make up an
oil passage 192 that supplies oil discharged from the discharge
port 84b of the engine-driven pump P2 to the discharge port 82b of
the differential gear-driven pump P1. The oil passage 192 includes
the orifice 184.
[0107] With the above configuration, when the engine-driven pump P2
is driven and oil discharged from the discharge port 84b of the
engine-driven pump P2 is supplied to the discharge port 82b of the
differential gear-driven pump P1 during reverse drive, a power that
acts in the reverse travel direction can be applied to the drive
wheels 14 by operating the differential gear-driven pump P1 as a
hydraulic motor. When the opening degree of the orifice 184 is
adjusted, the amount of oil that is supplied to the differential
gear-driven pump P1 can be adjusted, so a power that is transmitted
to the drive wheels 14 via the differential gear-driven pump P1 can
be appropriately adjusted. The structure is simpler than that of
the case where the change-over valve 78 is provided as in the case
of the lubrication and cooling system 70 of the above-described
first embodiment, so mountability is also high.
[0108] As described above, even when the orifice 184 is used
instead of the change-over valve 78 shown in FIG. 3 of the
above-described first embodiment, the differential gear-driven pump
P1 can be operated as a hydraulic motor, so similar advantageous
effects to those of the above-described first to third embodiments
are obtained.
[0109] FIG. 12 is the schematic configuration of a hybrid vehicle
200 (hereinafter, referred to as vehicle 200) according to a fifth
embodiment of the disclosure. The vehicle 200 includes the engine
12 that serves as a driving force source, the first electric motor
MG1 connected to the engine 12 such that power is transmittable,
the second electric motor MG2 that serves as a driving force
source, and a clutch C inserted between the engine 12 and the
differential gear set 20. The vehicle 200 includes the differential
gear-driven pump P1 and the engine-driven pump P2. The differential
gear-driven pump P1 is driven by the differential ring gear 38 (see
FIG. 1, or the like) of the differential gear set 20. The
engine-driven pump P2 is driven by the engine 12.
[0110] The vehicle 200 is configured to be able to shift into the
hybrid drive mode (HV mode) and the motor drive mode (EV mode). In
the hybrid drive mode (HV mode), the vehicle 200 travels by using
the engine 12 and the second electric motor MG2. In the motor drive
mode (EV mode), the vehicle 200 travels by using a power that is
output from the second electric motor MG2. For example, when the
clutch C is engaged, the engine 12 is connected to the drive wheels
14 via the clutch C such that power is transmittable, so the
vehicle 200 is able to travel in the HV mode by using the engine 12
and the second electric motor MG2. Therefore, during forward travel
in the HV mode, the engine 12 and the second electric motor MG2 are
used as the driving force sources. When the clutch C is released,
connection of the engine 12 and the drive wheels 14 is interrupted,
so the vehicle 200 travels in the EV mode by using the second
electric motor MG2. Therefore, during forward travel in the EV
mode, the second electric motor MG2 is used as the driving force
source.
[0111] During reverse travel, the clutch C is released, and a power
that acts in the reverse travel direction is output from the second
electric motor MG2. In other words, during reverse travel, only the
second electric motor MG2 is used as the driving force source. In
this way, the vehicle 200 travels by using only the power of the
second electric motor MG2 during reverse travel, so there are
concerns about shortage of driving force.
[0112] In this regard, in the fifth embodiment as well, an oil
passage 202 that is able to supply oil discharged from a discharge
port of the engine-driven pump P2 to a discharge port of the
differential gear-driven pump P1 during reverse travel is provided.
The oil passage 202 is configured to be communicated or interrupted
by a change-over valve 204 provided in the oil passage 202.
[0113] In the thus configured vehicle 200, during reverse travel, a
power that is output from the second electric motor MG2 to act in
the reverse travel direction is transmitted to the drive wheels 14
in a state where the clutch C is released. The engine-driven pump
P2 is driven by the engine 12 or the first electric motor MG1. Oil
discharged from the discharge port of the engine-driven pump P2 is
supplied to the discharge port of the differential gear-driven pump
P1 through the oil passage 202. As a result, the differential
gear-driven pump P1 is rotated in the reverse direction, and the
differential gear-driven pump P1 is operated as a hydraulic motor.
Thus, a power generated in the differential gear-driven pump P1 is
applied to the drive wheels 14 via the differential gear set 20, so
shortage of driving force during reverse travel is resolved.
[0114] As described above, even with the vehicle 200 of the fifth
embodiment, a power generated in the differential gear-driven pump
P1 is transmitted to the drive wheels 14 via the differential gear
set 20 during reverse travel, so similar advantageous effects to
those of the above-described first to fourth embodiments are
obtained.
[0115] FIG. 13 shows the schematic configuration of a hybrid
vehicle 300 (hereinafter, referred to as vehicle 300) according to
a sixth embodiment of the disclosure. The vehicle 300 includes the
engine 12 that serves as a driving force source, an electric motor
MG that serves as a driving force source, the clutch C inserted
between the engine 12 and the electric motor MG, and a transmission
T/M provided in a power transmission path between the electric
motor MG and the drive wheels 14. The vehicle 300 includes the
differential gear-driven pump P1 and the engine-driven pump P2. The
differential gear-driven pump P1 is driven by the differential ring
gear 38 (see FIG. 1, or the like) of the differential gear set 20.
The engine-driven pump P2 is driven by the engine 12.
[0116] The vehicle 300 is configured to be able to shift into the
hybrid drive mode (HV mode) and the motor drive mode (EV mode). In
the hybrid drive mode (HV mode), the vehicle 300 travels by using
the engine 12 and the electric motor MG. In the motor drive mode
(EV mode), the vehicle 300 travels by using a power that is output
from the electric motor MG. For example, when the clutch C is
engaged, the engine 12 is connected to the drive wheels 14 via the
clutch C, the electric motor MG, the transmission T/M, and other
components, such that power is transmittable, so the vehicle 300 is
able to travel in the HV mode by using the engine 12 and the
electric motor MG. Therefore, during forward travel in the HV mode,
the engine 12 and the electric motor MG are used as the driving
force sources. When the clutch C is released, connection of the
engine 12 and the drive wheels 14 is interrupted, so the vehicle
300 travels in the EV mode by using the electric motor MG.
Therefore, during forward travel in the EV mode, the electric motor
MG is used as the driving force source.
[0117] During reverse travel, the clutch C is released, a power
that acts in the reverse travel direction is output from the
electric motor MG, and the power is transmitted to the drive wheels
14 via the transmission T/M, the differential gear set 20, and
other components. In other words, during reverse travel, only the
electric motor MG is used as the driving force source. In this way,
the vehicle 300 travels by using only the power of the electric
motor MG during reverse travel, so there are concerns about
shortage of driving force.
[0118] In this regard, in the sixth embodiment as well, an oil
passage 302 that is able to supply oil discharged from a discharge
port of the engine-driven pump P2 to a discharge port of the
differential gear-driven pump P1 during reverse travel is provided.
The oil passage 302 is configured to be communicated or interrupted
by a change-over valve 304 provided in the oil passage 302.
[0119] In the thus configured vehicle 300, during reverse travel, a
power that is output from the electric motor MG is transmitted to
the drive wheels 14 via the transmission T/M in a state where the
clutch C is released. The engine-driven pump P2 is driven by the
engine 12. Oil discharged from the discharge port of the
engine-driven pump P2 is supplied to the discharge port of the
differential gear-driven pump P1 through the oil passage 302. As a
result, the differential gear-driven pump P1 is rotated in the
reverse direction, and the differential gear-driven pump P1 is
operated as a hydraulic motor. Thus, a power generated in the
differential gear-driven pump P1 is applied to the drive wheels 14
via the differential gear set 20, so shortage of driving force
during reverse travel is resolved.
[0120] As described above, even with the vehicle 300 of the sixth
embodiment, a power generated in the differential gear-driven pump
P1 is transmitted to the drive wheels 14 via the differential gear
set 20 during reverse travel, so similar advantageous effects to
those of the above-described first to fifth embodiments are
obtained.
[0121] The embodiments of the disclosure are described in detail
with reference the drawings; however, the disclosure is also
applicable to other embodiments.
[0122] For example, the above-described embodiments are not
necessarily implemented solely and may be implemented in
combination as needed. For example, the electric oil pump EOP may
be used instead of the engine-driven pump P2 of the lubrication and
cooling system 182 of the above-described fourth embodiment. In the
above-described third embodiment, each of Mode 1 to Mode 8 shown in
FIG. 6 includes the engine-driven pump P2 that is driven by the
engine 12. Alternatively, the electric oil pump EOP may be used
instead of the engine-driven pump P2.
[0123] In the above-described fifth embodiment, the vehicle 200
includes the engine-driven pump P2 that is driven by the engine 12
or the first electric motor MG1. Alternatively, the electric oil
pump EOP may be used instead of the engine-driven pump P2. In the
vehicle 200, an orifice may be provided instead of the change-over
valve 204 provided in the oil passage 202 that connects the
discharge port of the differential gear-driven pump P1 and the
discharge port of the engine-driven pump P2.
[0124] In the above-described sixth embodiment, the vehicle 300
includes the engine-driven pump P2 that is driven by the engine 12.
Alternatively, the electric oil pump EOP may be used instead of the
engine-driven pump P2. In the vehicle 300, an orifice may be
provided instead of the change-over valve 304 provided in the oil
passage 302 that connects the discharge port of the differential
gear-driven pump P1 and the discharge port of the engine-driven
pump P2.
[0125] In the above-described embodiments, the differential
gear-driven pump P1 is coupled to the differential ring gear 38 of
the differential gear set 20 such that power is transmittable;
however, the disclosure is not necessarily limited to the
configuration that the differential gear-driven pump P1 is coupled
to the differential ring gear 38. For example, the differential
gear-driven pump P1 may be driven by the counter gear 28 provided
on the counter shaft 32. In short, a rotating member that rotates
with the rotation of the drive wheels 14, that is, a rotating
member that is mechanically coupled to the drive wheels 14, can be
employed as the one that drives the differential gear-driven pump
P1 as needed.
[0126] In the above-described embodiments, the engine-driven pump
P2 is connected to the engine 12 via the input shaft 23 such that
power is transmittable; however, the engine-driven pump P2 is not
necessarily limited to this configuration. For example, the
engine-driven pump P2 may be directly driven by the crankshaft of
the engine 12. In short, the engine-driven pump P2 may be modified
as needed as long as the engine-driven pump P2 is driven via a
rotating member that is mechanically coupled to the engine 12.
[0127] In the above-described embodiments, oil is supplied to the
gears in the gear chamber 58, the bearings in the gear chamber 58,
the first electric motor MG1, the second electric motor MG2, and
the gears and bearings of the planetary gear train 24 as the
components to be cooled or lubricated; however, the components to
be cooled or lubricated are not necessarily limited to these
components. In short, as long as components are required to be
lubricated or cooled during travel, components to be cooled or
lubricated can be modified as needed according to the structure of
a vehicle.
[0128] The above-described embodiments are only illustrative. The
disclosure may be implemented in modes including various
modifications or improvements based on the knowledge of persons
skilled in the art.
* * * * *